Dispenser for flexible sheet material and a perforating mechanism adapted to be used therein

ABSTRACT

A mechanism for perforating a web of flexible sheet material which is adapted to be used in a flexible sheet material dispenser, said mechanism comprising; a rotatably mounted roller, a rotatably mounted knife positioned adjacent the roller and having a radially outward portion defining a cutting edge for perforating the web as the web passes between the roller and the knife, the roller being operatively connected to the knife for synchronous rotation therewith and having a slot therein for receiving the radially outward knife portion as the knife rotates past the roller, and means associated with the knife for orienting the cutting edge substantially in the direction in which the radially outward knife portion moves with respect to the web during the entrance of the portion into the slot so that when the portion enters the slot the cutting edge will effectively perforate the web.

RELATED APPLICATION

The present application is a divisional application of application Ser.No. 793,808, filed Jan. 24, 1969, now U.S. Pat. No. 3,575,328.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to dispensers, and specifically to a flexiblesheet material dispenser and a mechanism adapted to be used therein forperforating a web of flexible sheet material.

2. Description of the Prior Art

Dispensers for flexible sheet material, such as paper toweling have longbeen known which include mechanisms for perforating or severing a web ofsuch material to divide the web into individual sheets. Representativeof such dispensers are those disclosed in Hamilton et al. U.S. Pat. No.1,133,640; Schroeder U.S. Pat. No. 1,449,062; Shelley U.S. Pat. No.1,543,299; Walsh et al. U.S. Pat. No. 2,278,029; and Agamaite U.S. Pat.No. 2,560,061. The perforating or severing mechanisms used in thesedispensers generally include a rotatably mounted knife and a cooperatingrotatably mounted roller having a slot therein for receiving theradially outward portion of the knife as the knife rotates past theroller. The web of flexible sheet material is passed between the rollerand the knife to be perforated or severed when the radially outwardknife portion enters the slot in the roller.

Such mechanisms are satisfactory for perforating or severing relativelyunstretchable flexible sheet materials, such as uncreped paper toweling.However, with the increased use of relatively stretchable flexible sheetmaterials, such as embossed and creped paper toweling, the prior artperforating and severing mechanisms have provided unsatisfactory becausethe web of sheet material tends to stretch about the cutting edge of theknife instead of being perforated or severed thereby. This problemresults principally from the orientation of the cutting edge during theentrance of the radially outward knife portion into the slot; thecutting edge being oriented nonparallel to the direction in which theradially outward knife portion moves with respect to the web, causingthe edge to slide along the web. Although precision rotary shears areknown which could be employed for obviating this problem, for example,the rotary shears shown in Kalko U.S. Pat. No. 1,989,012, such shearsare much too expensive to be used in flexible sheet material dispensersdesigned for installation in both commercial and private washrooms andkitchens.

SUMMARY OF THE INVENTION

The perforating mechanism of the present invention offers an economicalsolution to the above-described deficiency of the perforating andsevering mechanisms used in the prior art flexible sheet materialdispensers.

Basically described, the perforating mechanism of the inventioncomprises; a chassis, a roller rotatably mounted on the chassis, a kniferotatably mounted on the chassis adjacent the roller and having aradially outward portion defining a cutting edge for perforating a webof flexible sheet material as the web passes between the roller and theknife, the roller being operatively connected to the knife forsynchronous rotation therewith and having a slot therein for receivingthe radially outward portion as the knife rotates past the roller, andmeans associated with the knife for orienting the cutting edgesubstantially in the direction in which the radially outward knifeportion moves with respect to the web during the entrance of the portioninto the slot so that when the portion enters the slot the cutting edgewill effectively perforate the web.

A web guiding means preferably is employed in conjunction with theperforating mechanism which holds the web of flexible sheet materialtautly about the roller at all times to further reduce any tendency ofthe web to stretch about the cutting edge of the knife.

The dispenser of the invention, in which the abovedescribed perforatingmechanism is adapted to be used, preferably includes an adjustable stopmechanism for stopping the rotation of the knife and the roller and thusarresting the movement of the web with the perforations last-produced inthe web either outside or inside the dispenser so that when anindividual sheet of material is torn from the web along suchlast-produced perforations, the leading edge of the web may or may notbe immediately accessible to a user, as desired.

With the foregoing in mind, it is an object of the present invention toprovide a flexible sheet material dispenser having a mechanism foreffectively perforating a web of flexible sheet material, andparticularly a web of relatively stretchable flexible sheet material.

It is also an object of the invention to provide a mechanism forperforating a web of flexible sheet material which mechanism includes aknife and a means for orienting the cutting edge thereof in thedirection which is most effective for perforating the web.

It is a further object of the invention to provide a flexible sheetmaterial dispenser which includes an adjustable stop mechanism forregulating the position of the leading edge of a web of flexible sheetmaterial such that the leading edge may be positioned either outside orinside the dispenser and thus be either immediately or not immediatelyaccessible to a user.

It is an additional object of the invention to provide a flexible sheetmaterial dispenser having a mechanism for perforating a web of flexiblesheet material, which dispenser embodies a compact and rugged structureand which is economical to manufacture, and thus is ideally suited forboth commercial and private installations.

These and other objects of the invention will become apparent upon aconsideration of the detailed description of the preferred embodimentsthereof given in connection with the following drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view of the dispenser of the invention;

FIG. 2 is a right end view of the dispenser shown in FIG. 1;

FIG. 3 is a front view of the dispenser shown in FIG. 1 with the housingthereof shown in cross-section;

FIG. 4 is a right end view of the dispenser shown in FIG. 1 with thehousing thereof shown in cross-section;

FIG. 5 is a left end view of the dispenser shown in FIG. 1 with thehousing thereof shown in cross-section;

FIG. 6 is a sectional view taken on line 6--6 of FIG. 5;

FIG. 7 is a sectional view taken on line 7--7 of FIG. 5 with selectedelements of the dispenser being broken away for clarity;

FIG. 8 is a sectional view taken on line 8--8 of FIG. 7;

FIG. 9 is a sectional view taken on line 9--9 of FIG. 4;

FIG. 10 is an enlarged elevational view of the stop mechanism andassociated elements used in the dispenser shown in FIG. 1;

FIG. 11 is a sectional view of one of the vacuum cups of the timingmeans used in the dispenser shown in FIG. 1;

FIG. 12 is an elevational view of the knife of a first embodiment of theperforating mechanism of the invention, which mechanism may be used inthe dispenser shown in FIG. 1;

FIG. 13 is an elevational view of one of the knife mounting brackets forthe knife shown in FIG. 12;

FIG. 14 is an elevational view of a knife roller assembly for rotatablysupporting the knife shown in FIG. 12;

FIG. 15 is an elevational view of the slot roller used in conjunctionwith the knife shown in FIG. 12;

FIG. 16 is a sectional view taken on line 16--16 of FIG. 14;

FIG. 17 is a sectional view taken on line 17--17 of FIG. 15;

FIG. 18 is an elevational view of a knife roller assembly for rotatablysupporting the knife of a second embodiment of the perforating mechanismof the invention, which mechanism also may be used in the dispensershown in FIG. 1;

FIG. 19 is an elevational view of the slot roller used in conjunctionwith the knife shown in FIG. 18;

FIG. 20 is a sectional view taken on line 20--20 of FIG. 18;

FIG. 21 is a sectional view taken on line 21--21 of FIG. 19;

FIG. 22 is a schematic sectional view of a third embodiment of theperforating mechanism of the invention which mechanism also may be usedin the dispenser shown in FIG. 1; and

FIG. 23 is a diagrammatic-sectional view showing the operation of theperforating mechanism which is composed of the knife roller assemblyshown in FIG. 14 and the slot roller shown in FIG. 15.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The dispenser of the invention is designated in the drawings byreference numeral 10, and basically comprises a chassis 12 (FIG. 3), asupporting means 14 (FIG. 6) for rotatably supporting a roll of flexiblesheet material, such as a roll of creped paper toweling 150, a guidingmeans 16 (FIGS. 4 and 5) for guiding a web of paper toweling 160 fromroll 150 to a position to be grasped by a user so that the user may pullthe web out of dispenser 10, and a perforating mechanism 18 (FIGS. 5 and8) for perforating web 160 at intervals therealong to divide the webinto individual sheets.

THE CHASSIS AND THE HOUSING

Chassis 12 includes a back plate 20 (FIGS. 2 and 4-8) which is adaptedto be secured to a wall 21 (FIG. 2) by suitable fasteners, such asscrews 22. Integral with back plate 20 are a left end flange 24 (FIG. 5)and a right end flange 26 (FIG. 4). A left end plate 28 is affixed toleft end flange 24 by suitable fasteners, such as sheet metal screws 30.A right end plate 32 is similarly affixed to right end flange 26 bysuitable fasteners, such as sheet metal screws 34. A bottom plate 36(FIGS. 4, 5, 7 and 8) extends forwardly from the bottom of back plate 20and curves upwardly near the front of the dispenser, terminating in anupstanding arcuate portion 38. The rear portion of bottom plate 36 has aplurality of holes 40 therein which register with a correspondingplurality of lugs 42 that are carried by a bottom flange 44 integralwith back plate 20. Also, the rear portion of bottom plate 36 isconnected to left end plate 28 and right end plate 32 by tabs 29 and 33,respectively; the tabs being integral with the end plates and being spotwelded to the bottom plate. The forward portion of bottom plate 36 isconnected to left end plate 28 by tabs 46, 47 and 48 (FIG. 5) and toright end plate 32 by tabs 50, 51 and 52 (FIG. 8); the tabs beingintegral with the bottom plate and being spot welded to the end plates.A plurality of louvers 54 (FIGS. 7 and 8) are formed in bottom plate 36to permit air to circulate within dispenser 10.

Chassis 12 also includes a stripper 56 (FIGS. 3, 5, 7 and 8) having aplurality of upstanding arcuate fingers 58, the function of which isdescribed below, and which is attached to left end plate 28 and to rightend plate 32 by tabs 60 and 62, respectively; the tabs being integralwith the stripper and being spot welded to the end plates. An arcuateshield 64 (FIGS. 5, 7 and 8) extends upwardly from approximately themidpoint of bottom plate 36 and forwardly to the upward extremity ofarcuate bottom plate portion 38. The lower portion of shield 64 isdefined by a flange 66 having a plurality of holes 68 therein whichregister with a corresponding plurality of lugs 70 carried by bottomplate 36. The upper portion of shield 64 is connected to left end plate28 by tabs 72 and 74, and to right end plate 32 by tabs 76 and 78; thetabs being integral with the shield and being attached to the end platesby suitable fasteners, such as sheet metal screws 80. Shield 64 andbottom plate 36 defined an elongated cavity 82 within dispenser 10within which guiding means 16 and perforating mechanism 18 are disposed.The right end of cavity 82 is enclosed by right end plate 32 and theleft end of the cavity is enclosed by a cover plate 84 (FIGS. 5 and 7).Cover plate 84 is connected to left end plate 28 by a plurality ofsuitable fasteners, such as sheet metal screws 86 which engage acorresponding plurality of bosses 88 formed in the end plate. Aremovable cover plate, such as plate 84, is used for enclosing the leftend of cavity 82 so that access readily may be had to the interior ofthe cavity for servicing guiding means 16 and perforating mechanism 18.

Chassis 12 is enclosed by a housing 90 (FIGS. 1 and 2). Housing 90comprises an upper portion 92, a cap portion 94, a lower front portion96, a lower left end portion 98, and a lower right end portion 100. Capportion 94 is attached to upper portion 92 by a plurality of tabs 102(FIGS. 4 and 5). The other portions of the housing are connectedtogether in an appropriate manner, such as by spot welding the portionstogether where the edges thereof overlap. Lower front portion 96 definesan opening 104 through which web 160 (FIG. 3) may be withdrawn fromdispenser 10 by a user, as described below. Lower left and right endportions 98 and 100 each include an integral bottom flange (FIGS. 3-5, 8and 9) which is adapted to enclose the respective, left or right outerportions of bottom plate 36.

Housing 90 is connected to chassis 12 by pivot pins 106 and 108; pin 106pivotally connecting lower left end housing portion 98 to left endflange 24 of back plate 20, and pin 108 pivotally connecting lower rightend housing portion 100 to right end flange 26 of back plate 20. Thisarrangement permits housing 90 to be pivoted outwardly about pins 106and 108 away from chassis 12 to expose the internal elements ofdispenser 10. A lock 110 preferably is attached to the rear of capportion 94 for releasably securing the housing to the chassis to preventunauthorized access to the interior of the dispenser. Lock 110preferably is a combination locking and latching device of the typedisclosed in U.S. Pat. No. 3,500,667 owned by the assignee of thepresent application.

THE SUPPORTING MEANS

Supporting means 14 comprises a pair of substantially horizontallyopposed supporting members 110 and 112 (FIGS. 3-6). Supporting member110 (FIGS. 3, 5 and 6) is mounted at the left end of chassis 12 andincludes a mounting bracket 114 and a hub 116. Mounting bracket 114 isattached to back plate 20 and left end flange 24 by suitable fasteners,such as sheet metal screws 118. Hub 116 is attached to the forward endof bracket 114 by suitable fasteners, such as sheet metal screws 120.Hub 116 has a recess 122 therein defined by an arcuate bearing surface124 and the arcuate inner edge of a guide lip 126.

Supporting member 112 (FIGS. 3, 4 and 6) is mounted at the right end ofchassis 12 and includes a flexible mounting bracket 128 and a hub 130.Mounting bracket 128 is attached to back plate 20 by suitable fasteners,such as sheet metal screws 132. Hub 130 is attached to the forward endof bracket 128 by suitable fasteners, such as sheet metal screws 134,and carries a pair of lugs 136 which register with a corresponding pairof slots formed in the bracket. Hub 130, similarly to hub 116, has arecess 138 therein defined by an arcuate bearing surface 140 and theinner arcuate edge of a guide lip 142.

A braking spring 144 has one end affixed to the inner surface of hub 130by as suitable fastener, such as rivet 146, and extends rearwardly fromhub 130, between lugs 136, and terminates adjacent back plate 20.

Supporting means 14 is adapted to rotatably support roll 150. The rollpreferably is of the type disclosed as the first embodiment (FIGS. 1 -3) in U.S. Pat. No. 3,438,589 owned by the assignee of the presentapplication. The roll has a unipartite internal supporting means 152comprising a cylindrical core 154 and a pair of trunnion members 156 and158 attached to the ends of the core. The outer ends of trunnion members156 and 158 extend axially outwardly beyond the ends of roll 150, andare adapted to engage recesses 122 and 138, respectively. The outer endsof the trunnion members have different cross-sectional dimensions; andrecesses 122 and 138 have different internal dimensions corresponding tothe cross-sectional dimensions of the outer ends of the trunnionmembers. Thus, roll 150 may be supported by supporting means 14 onlywhen each recess is enagaged by the trunnion member outer end having across-sectional dimension corresponding to the internal dimension ofthat recess; and specifically only when recess 122 is engaged by theouter end of trunnion member 156 and recess 138 is engaged by the outerend of trunnion member 158. This feature insures that roll 150 will beplaced in dispenser 10 in the proper manner for web 160 to be passedthrough guiding means 16 and perforating mechanism 18, and out of thedispenser through opening 104.

To insert roll 150 into supporting means 14, the outer ends of trunnionmembers 56 and 158 are placed against guide lips 126 and 142,respectively, and the roll is then pushed rearwardly. When this occursbracket 128 will flex outwardly permitting the outer ends of thetrunnion members to engage, and seat in, recesses 122 and 138. After theroll has been thus inserted into the supporting means, flexible mountingbracket 128 urges hub 130 toward hub 116 to prevent any inadvertentdisengagement of the roll.

As the roll is inserted into the supporting means, the roll end nearestspring 144 will contact the spring and move the spring outwardly to theposition shown in solid lines in FIG. 6. Thereafter, as web 160 iswithdrawn from the roll, spring 144 will frictionally engage the rollend and brake the rotation of the roll, to thus prevent uncontrolledspinning thereof.

THE GUIDING MEANS AND THE PERFORATING MECHANISM

Guiding means 16 includes an upper pinch roll 162 and a lower pinch roll164 (FIGS. 3 - 5 and 8). Upper pinch roll 162 is mounted on stub shafts166 and 168 which are journaled for rotation in cover plate 84 and rightend plate 32, respectively. Similarly, lower pinch roll 164 is mountedon sub shafts 170 and 172 which are also journaled for rotation in coverplate 84 and right end plate 32, respectively.

Perforating mechanism 18 includes a roller 174 (FIGS. 3 - 5, 7, 8, 15and 17) which is positioned between pinch rolls 162 and 164 and whichhas an intermittent helical slot 176 therein. Slot 176 extends generallyaxially of roller 174 and opens radially outwardly from the surfacethereof. The slot roller is supported by stub shafts 178 and 180 whichare journaled for rotation in cover plate 84 and right end plate 32,respectively. Perforating mechanism 18 also includes a knife 182 whichis rotatably mounted by a roller 184. Roller 184 is supported by stubshafts 186 and 188 which are journaled for rotation in cover plate 84and right end plate 32, respectively. The bearing surfaces for shafts178, 186, 180 and 188 preferably comprise low-friction bushings 190,194, 192 and 196, respectively; the former two bushings being secured tocover plate 84 and the latter two to right end plate 32.

Stub shafts 166, 170, 168 and 172 are journaled by elongated bearingsurfaces 198, 202, 200 and 204, respectively; the former two surfacesbeing integrally formed in cover plate 84 and the latter two beingintegrally formed in right end plate 32. This arrangement permits eachof the pinch rolls to move into contact with slot roller 174 to form anip therebetween. A biasing spring 206 is connected to stub shafts 166and 170, and a similar biasing spring 208 is connected to stub shafts168 and 172 for urging the pinch rolls toward the slot roller. Biasingsprings 206 and 208 are held in position by U-shaped brackets 210, oneof which is attached to cover plate 84 and another of which is attachedto right end plate 32 in any convenient manner, such as by spot welding.In order to permit the surfaces of lower pinch roll 164 and slot roller174 to contact one another, the upstanding arcuate portion 38 of bottomplate 36 comprises a plurality of spaced apart, relatively narrowarcuate strips 212 (FIG. 7), and pinch roll 164 has a plurality ofcircumferential slots 214 therein (FIG. 3), within which strips 212 areaccommodated.

From roll 150, web 160 is directed around upper pinch roll 162, betweenthe upper pinch roll and slot roller 174, around the slot roller,between the slot roller and lower pinch roll 164, around the lower pinchroll and out of the dispenser through opening 104. As will be apparentfrom the foregoing description, pinch rolls 162 and 164 insure that web160 will be held tautly about slot roller 174 at all times. When a userwithdraws the web from the dispenser by exerting a pulling force on theleading edge thereof, pinch roll 164 will move slightly out of contactwith slot roller 174; however, as soon as the pulling force is relaxedbiasing springs 206 and 208 will immediately move the pinch roll backinto contact with the slot roller.

Slot roller 174 also has a plurality of circumferential slots 216therein, within which are accommodated fingers 58 of stripper 56.Fingers 58 insure that web 160 will be directed out of opening 104instead of adhering to the slot roller and becoming wound thereabout.

Knife 182 is helically twisted along the length thereof and includes aradially outward portion 217 which is curved forwardly in the directionof rotation of the knife and which defines a serrated cutting edge 220(FIGS. 4, 5, 7, 8, 12, 14 and 16). The knife also has a plurality ofnotches 218 therein within which strips 212 of bottom plate portion 38are accommmodated as the knife rotates into proximity with and past slotroller 174. As the knife rotates past the slot roller, radially outwardknife portion 217 enters slot 176 and cutting edge 220 progressivelyperforates the entire width of web 160 except for the sections of theweb that are aligned with notches 218. The unperforated sections of theweb have sufficient tensile strength to permit a user to draw the webout of the dispenser by exerting a smooth, continuous pulling forcethereon. However, after the web has been perforated, an abrupt increasein the pulling force will cause the web to part along the perforationslast-produced therein by cutting edge 220.

Knife 182 is attached to knife roller 184 by a pair of mounting brackets222. The knife is first affixed to the mounting brackets, convenientlyby welding, and a helical twist is then imparted to the knife and thebrackets. The brackets are thereafter attached to roller 184 by aplurality of bolts 224 which threadably engage a pair of hubs 226disposed internally of the roller at the ends thereof. The knife andmounting brackets are bowed slightly outwardly at the centers thereof(FIGS. 12 and 13) so that after the helical twist is imparted thereto,the entirety of the radially inward surfaces thereof will abut thesurface of roller 184. Additional bolts 224 may be used for securingroller 184 to hub 226 to insure that the hubs are firmly anchored withinthe roller.

Slot roller 174 and knife roller 184 are operatively interconnected toinsure that the rollers will rotate in synchronism with one another. Forthis purpose a gear 226 is affixed to one end of the slot roller whichengages and meshes with a gear 228 affixed to the same end of the kniferoller. In the embodiment shown in the drawings, gear 228 has twice asmany teeth as does gear 226, so that the slot roller will rotate attwice the rotational speed of the knife roller. Due to this differencein the rotational speeds of the two rollers, slot 176 must be twistedthrough an arc which is twice as large as the arc through which theknife 182 is twisted. Thus, the knife may be helically twisted throughan arc of 45° (FIG. 16) and slot 176 helically twisted through an arc of90° (FIG. 17).

To preclude slippage of web 160 about the slot roller, the rollerpreferably is made from a substance having a relatively high coefficientof friction, such as rubber. When a user exerts a pulling force on theleading edge of the web, the frictional force exerted by the web on theslot roller causes the slot and knife rollers to rotate in synchronismwith one another.

The path of movement of cutting edge 220 with respect to slot 176 duringthe perforating cycle of the knife is shown in FIG. 23 by dashed line221. Also shown in this figure are the relative positions of edge 220and a point 225 on the knife located at the radially outward extremityof brackets 222; the positions of the former by points 0', 2', 4', 6',8', 10', 12', 14', 16' and 18', and the corresponding positions of thelatter by points 0", 2", 4", 6", 8", 10", 12", 14", 16" and 18".

The positions of radially outward knife portion 217 with respect to slot176 during the perforating cycle are indicated by the broken lines whichconnect the corresponding positional points of edge 220 and point 225i.e., lines 0' -- 0", 2' -- 2", 4' -- 4", 6' -- 6", 8' -- 8", 10' --10", 12' -- 12" , 14' -- 14", 16' -- 16" and 18' -- 18". As shown, whileportion 217 is moving from position 0' -- 0" to position 6' -- 6", i.e.,during the entrance of the portion into slot 176, cutting edge 220 isoriented substantially in the same direction as the direction in whichportion 217 is moving.

The same relationship between the orientation of the cutting edge andthe movement of portion 217 is maintained with respect to web 160 as ismaintained with respect to slot 176. Thus, as described above, web 160is held tautly about slot roller 174 by pinch rolls 162 and 164 and bythe pulling force exerted on the web by a user. As a consequence of thisfeature when slot 176 rotates into proximity with knife 220 the portionof the web which overlies the slot is curved in conformance with thecurvature of the surface of roller 174, and there is no relativemovement therebetween. Thereafter, when portion 217 reaches position 0'-- 0" and slot 176 reaches the position shown in FIG. 23, i.e., whencutting edge 220 initially contacts web 160, the orientation of thecutting edge substantially coincides with the direction in which portion217 is moving with respect to the web. This relationship is maintainedas portion 217 moves from position 0' -- 0" to position 6' -- 6", i.e.,during the entrance of the portion into the slot. Thus, the forwardcurvature of portion 217 orients cutting edge 220 substantially in thedirection in which portion 217 moves with respect to the web, as well aswith respect to slot 176, during the entrance of the portion into theslot.

The structure and resulting operation of perforating mechanism 18provides several advantages over the prior art perforating and severingmechanisms. The orientation of the cutting edge results in an effectiveperforation of the flexible sheet material web by reducing any tendencyof the edge to slide along the web. Also, the mechanism is economical tomanufacture, and embodies a rugged and compact structure which is ableto withstand the prolonged and abusive wear encountered in commercialwashroom and kitchen installation.

THE STOP MECHANISM AND THE TIMING MEANS

Dispenser 10 also includes a mechanism 223 (FIGS. 4 and 10) for stoppingthe rotation of knife roller 184 and slot roller 176 abruptly and thusarresting the movement of web 160 abruptly, so that an individual sheetof paper toweling may be torn from web 160 along the perforationslast-produced therein by knife 182. Stop mechanism 233 includes stoplever 230 which is pivotally connected to right end plate 32 by a pivotpin 232 and has a cam follower 234 and a stop lug 236 integrally affixedthereto. The stop mechanism also includes a feed wheel 240 which issecured to the end of stub shaft 188, being one of the shafts whichsupport knife roller 184, and has a camming pin 238 affixed thereto.Camming pin 238 is adapted to coact with camming pin 234 and stop lug236 to stop the rotation of knife roller 184 and slot roller 174. As theknife roller is rotated incident to the exertion of a pulling force onweb 160 by a user, camming pin 238 is rotated about the axis of shaft188. While the knife roller is rotating, stop lever 230, cam follower234 and stop lug 236 are in the positions shown in full lines in FIG.10. In this position, the cam follower is positioned in the rotationalpath of camming pin 238, so that when the pin reaches the position shownin full lines in FIG. 10, it engages the underside of, and cams thefollower upwardly. This action pivots stop lever 230, cam follower 234and stop lug 236 to the positions shown in dotted lines in FIG. 10. Inthis position, the stop lug is positioned in the rotational path ofcamming pin 238, so that when the pin disengages the underside of thecam follower, it thereafter engages the stop lug. This causes kniferoller 184 and slot roller 174 to stop abruptly and thus abruptlyarrests the movement of web 160, resulting in an abrupt increase in thepulling force exerted on the web. As explained above, this permits anindividual sheet of paper toweling to be torn from the web along theperforations last-produced therein by knife 182.

A timing means 237 is associated with stop mechanism 233 for regulatingthe length of time during which the stop mechanism is effective forpreventing the rotation of the knife and slot rollers. Timing means 237comprises a pair of opposed, resilient vacuum cups 242 and 244; cup 242being connected by a racket 246 to stop lever 230 and cup 244 beingattached by a mount 248 to a flange integral with right end plate 32.When camming pin 238 engages the underside of cam follower 234 andpivots stop lever 230 upwardly to position stop lug 236 in therotational path of the camming pin, vacuum cup 242 is pivoted rearwardlyinto vacuum-gripping relationship with cup 244. As long as cups 242 and244 remain in the rotational path of camming pin 238 and prevent kniferoller 184 and slot roller 174 from being rotated.

Preferably, vacuum cup 242 is made of a relatively hard resilientmaterial, such as hard rubber, and vacuum cup 244 is made of arelatively soft resilient material, such as soft rubber. Thisarrangement minimizes the compression force required to engage the cupsin vacuum-gripping relationship, yet provides a sufficientvacuum-gripping force between the cups, i.e., the force required to pullthe cups apart, to insure that the cups will not be pulled apart whencamming pin 238 engages stop lug 236. The resiliency of cups 242 and244, and particularly of relatively soft resilient cup 244, provides acushion for absorbing the dynamic forces generated by the abruptengagement of pin 238 with lug 236 and thus minimizes wearing of thestop mechanism components.

To regulate the period of time during which cups 242 and 244 remain invacuum-gripping relationship, a needle valve 250 (FIG. 11) is providedfor controlling the flow of ambient air into the vacuum environmentbetween the cups. Valve 250 is mounted in bracket 246 and communicateswith the interior of cup 242. The valve includes a cylindrical valvebody 252 having an aperture 253 formed therein, and a needle-tippedadjustment bolt 254 which threadably engages an end flange of bracket246. Bolt 254 is locked into position by a lock nut 255 which is alsothreadably engaged by the bolt and which abuts the end flange of bracket246. By adjusting the position of bolt 254 with respect to aperture 253,the rate at which ambient air flows into the vacuum environment betweenvacuum cups 242 and 244, and thus the period of time during which thecups remain in vacuum-gripping relationship, may be regulated. A returnspring 256 is connected between bracket 246 and the forward portion ofright end plate 32 for pivoting stop lever 230 downwardly, and thusmoving stop lug 236 out of the rotational path of camming pin 238, whenthe air pressure within the environment between vacuum cups 242 and 244has increased sufficiently to destroy the vacuum-gripping relationshipbetween the cups. The user may thereafter withdraw a further length ofweb 160 from the dispenser, which will be perforated by knife 182 in themanner described above and which may be torn from the web as anindividual sheet of paper toweling when stop mechanism 233 again stopsthe rotation of knife roller 184 and slot roller 174.

As mentioned above, feed wheel 240 is secured to the end of stub shaft188. Preferably, the wheel is secured to the shaft by a bolt (not shown)which threadably engages the shaft axially thereof. The cross-section ofthe end of shaft 188 is shaped as an equilateral triangle (FIGS. 4 and10), and feed wheel 240 has a similarly shaped opening in the centerthereof for accommodating the shaft end therein. The feed wheel may thusbe secured to shaft 188 in any one of three rotational positions. In onerotational position of the feed wheel (FIG. 4) camming pin 238 engagesstop lug 236 and the rotation of the knife and slot rollers stoppedbefore the perforations last-produced in web 160, indicated at P, havebeen drawn outside dispenser 10. After a user has torn an individualsheet of paper toweling from the web with the last-produced perforationsinside the dispenser, the leading edge of the web will thereafter bypositioned within the dispenser and thus not be immediately accessibleto the user. This mode of operation encourages economical consumption ofroll 150.

After the time period has elapsed during which timing means 237maintains stop mechanism 233 effective for preventing the rotation ofthe knife and slot rollers, the knife and slot rollers are rotatedautomatically by a feed means 258 to move the leading edge of the weboutside the dispenser. Feed means 258 comprises a lug 260 affixed tofeed wheel 240 and a feed spring 262 connected between lug 260 and therear portion of right end plate 32. Lug 260 is positioned with respectto camming pin 238 so that spring 262 will be extended when the cammingpin engages stop lug 236 (FIG. 4). Thus, when the stop lug is moved outof the rotational path of pin 238 by return spring 256, feed spring 262will contract and thereby impart rotation to feed wheel 240 and shaft188. Shaft 188 in turn will impart rotation to knife roller 184 and slotroller 174, thus moving the leading edge of web 160 outside thedispenser.

In the second rotational position of feed wheel 240 with respect toshaft 188 (FIG. 8) stop mechanism 233 will stop the rotation of theknife and slot rollers after the perforations last-produced in web 160,indicated at P are outside dispenser 10. In this mode of operation, theleading edge of the web is immediately accessible to a user after anindividual sheet of toweling has been torn therefrom along theperforations last-produced therein. When this mode of operation isemployed, bolt 254 preferably is adjusted so that the time period duringwhich the stop mechanism is effective for stopping the rotation of theknife and pinch rollers is of short duration, i.e., 1 - 2 seconds,permitting a second sheet of toweling to be obtainable as soon as thefirst sheet is torn from the web. As is apparent, this second mode ofoperation is less economical than the first mode, but is more convenientto the user's needs than the first mode. The first mode generally wouldbe employed where economical consumption of the paper toweling is asignificant factor, such as in commercial washroom installations, andthe second mode employed where user convenience is a significant factor,such as in a private kitchen installation. Dispenser 10 is thus ideallysuited for either commercial or private installations.

The third rotational position of feed wheel 240 with respect to shaft188 is not used because in this latter position, knife portion 217 wouldbe within slot 176 when the stop mechanism stopped the rotation of theknife and slot rollers. This would not only permit the web to be atleast partially torn along the perforations being produced therein atthat time, thus dividing the web before the perforations have passedbetween slot roller 174 and lower pinch roller 164, but also wouldimpose undesirable bending forces on blade 182.

Dispenser 10 also includes a means 265 for rotatably supporting apartially consumed roll of flexible sheet material, such as a partiallyconsumed roll or creped paper toweling 264 (FIG. 8). Supporting means265 comprises a pair of opposed flanges 266 and 268, which are integralwith back plate 20 (FIGS. 4, 5, 7 and 8). Flanges 266 and 268 extendforwardly from back plate 20 into a cavity 270 in the lower rear portionof the dispenser defined by the back plate, bottom plate 36 and shield64. Each of the flanges has a U-shaped cutout therein; flange 266 havingcutout 272 therein and flange 268 having cutout 274 therein. Theinternal dimensions of cutouts 272 and 274 corresponding to thecross-sectional dimensions of the outer ends of trunnion members 156 and158, respectively. Thus, after roll 150 has been partially consumed,being then designated roll 264, the roll may be moved from supportingmeans 14 to supporting means 265. When the roll is moved from supportingmeans 14 to supporting means 265, it is not necessary to withdraw web160 from guiding means 16 and perforating mechanism 18. The trunnionmembers are simply disengaged from supporting members 110 and 112, andinserted into cutouts 272 and 274. From this latter position the webextends along path 276 (FIG. 8) from the top of roll 264 to the top ofupper pinch roller 162.

After partially consumed roll 264 has been moved into cavity 270, afresh roll 150 may be inserted into supporting means 14 in the mannerdescribed above. The web from roll 150 is merely superimposed on the webfrom roll 264 and is passed through guiding means 16 and perforatingmechanism 18 in the manner described above. Thereafter, as long as anypaper toweling remains wound about partially consumed roll 264,dispenser 10 will dispense a double-ply thickness of the toweling.

This latter feature of the dispenser is particularly suited forcommercial installations where it is uneconomical to service thedispenser except at regular intervals, such as daily. In such instances,a custodian need not wait until a roll is completely consumed beforeservicing the dispenser; nor need he discard a partially consumed rollwhen servicing the dispenser at the end of a regularly establishedservice interval. He merely moves the partially consumed roll fromsupporting means 14 to supporting means 265, and inserts a fresh rollinto the former supporting means. To facilitate the custodian'sappraisal as to whether or not a fresh roll need be placed in thedispenser at the end of a regularly established service interval,viewing ports 278 (FIG. 2) are provided in upper housing portion 92adjacent an end of roll 150. By observing the diameter of the rollthrough ports 278, the custodian will be appraised of the amount oftoweling remaining on the roll.

To load dispenser 10, housing 90 is first pivoted outwardly from aboutchassis 12, thus exposing the internal elements of the dispenser. A rollof flexible sheet material, such as roll 150, is then inserted intosupporting means 14 as described above. The web from the roll, such asweb 160, is directed around upper pinch roll 162, with the leading edgeof the web resting on the forward surface of slot roller 174. Housing 90is then pivoted upwardly about chassis 12 to enclose the internalelements of the dispenser. Feed wheel 240 is thereafter turned in acounter-clockwise direction as viewed from the right end of thedispenser, causing the web to be fed through guiding means 16 andperforating mechanism 18. Arcuate strips 212 and lower pinch roll 164insure that the web will be guided, and held tautly, about slot roller174. To permit the feed wheel to be manipulated when the internalelements of the dispenser are enclosed by housing 90, a slot 280 isprovided in lower right end housing portion 100, through which the lowerportion of feed wheel 240 extends (FIG. 4).

Dispenser 10 also includes means for preventing feed wheel 240 frombeing rotated in the direction opposite to the proper direction forfeeding web 160 through the guiding means and the perforating mechanism.Such means include a ratchet mechanism 282 (FIG. 4) comprising anL-shaped pawl 284 which is pivotally connected to right end plate 32 bya pin 286. Inserted over the base of the pawl is a resilient sleeve 288which engages a plurality of notches 290 formed in periphery of feedwheel 240. As long as the feed wheel is rotated in the counter-clockwisedirection as viewed from the right end of dispenser 10, the base of pawl284 and sleeve 288 pivot freely in and out of notches 290. However, anyattempt to rotate the feed wheel in the opposite direction will causethe pawl to bind in one of the notches and prevent rotation of thewheel. A lug 292 carried by right end plate 32 is positioned above pawl284 to prevent the pawl from rotating completely about pin 286, thusinsuring that the pawl will remain in the proper position with respectto feed wheel 240 to prevent improper rotation of the wheel.

THE SECOND EMBODIMENT OF THE PERFORATING MECHANISM

A second embodiment of the perforating mechanism of the invention isshown in FIGS. 18-21. This latter embodiment of the perforatingmechanism may be employed in dispenser 10 instead of mechanism 18, andincludes an axially straight knife 300 which is attached to axiallystraight mounting brackets 302. In all other respects the knife rollerassembly of the second embodiment is identical to the knife rollerassembly of the first embodiment, including knife roller 184, stubshafts 186 and 188, and gear 228.

A slot roller 303 is used in conjunction with knife 300. Roller 303 issimilar to slot roller 174, except that instead of an intermittenthelical slot along the length thereof, roller 303 has an intermittentaxially straight slot 304 therein for accommodating the radially outwardportion of knife 300.

The only difference in operation between the first and secondperforating mechanism embodiments is that helically twisted knife 182 ofthe first embodiment perforates the web progressively, with only a smallsection of the cutting edge contacting the web at any one time. Thisarrangement requires only a relatively small force to be exerted againstthe web by the cutting edge to accomplish an effective perforation. Thecutting edge of knife 300, on the other hand, perforates the entirewidth of the web at one time, requiring a slightly greater perforatingforce. The advantage of the second embodiment over the first is that thelatter is somewhat more economical to manufacture, since the knife andmounting brackets need not be helically twisted.

THE THIRD EMBODIMENT OF THE PERFORATING MECHANISM

A third embodiment of the perforating mechanism of the invention isshown in FIG. 22. This embodiment also may be employed in dispenser 10instead of the first or second embodiments described above. The thirdembodiment of the perforating mechanism includes a substantially planarknife 306 which is pivotally mounted on a knife roller 307 by a pair ofstub shafts 310 affixed to each end of the knife and journaled in theends of the knife roller. Also affixed to each end of knife 306 arecamming lugs 312 which extend radially outwardly beyond the cutting edgeof the knife. Lugs 312 ae adapted to be engaged by cams 314 mounted oneach end of a slot roller 316 having an axial slot 318 therein. Asopposed to the previous embodiments, the surfaces of the knife roller308 and slot roller 316 contact each other, thereby eliminating thenecessity for a lower pinch roll for maintaining web 160 taut about theslot roller.

Knife 306 is normally biased forwardly by a small spring (not shown)through an arc of approximately 15° from a radial orientation withrespect to roller 308. Thus, when the knife enters slot 318, the cuttingedge thereof will be oriented substantially in the same direction as thedirection in which the radially outward portion of the knife is movingwith respect to web 106. In this respect, the perforating action ofknife 306 is similar to the perforating action of knives 182 and 300,described above.

After knife 306 moves into the slot, lugs 312 will be engaged by cams314. The cams pivot the lugs, and therefore knife 306, rearwardly withrespect to the direction of rotation of knife roller 308. This actionpermits slot 318 to be made narrow enough for the knife to perform aneffective perforation while maintaining the surfaces of the knife andslot rollers in contact with each other. After the knife has beenwithdrawn from the slot and lugs 312 have disengaged cams 314, thebiasing spring will again pivot knife 306 forwardly. To insure thatknife roller 308 and slot roller 316 rotate in synchronism with eachother, the rollers preferably are operatively connected together bygears, as described above in connection with the first and secondperforating mechanism embodiments.

The foregoing constitutes a detailed description of the dispenser andperforating mechanism of the invention, the latter being adapted to beused in the former, although not being restricted to use solely therein.Moreover, it is recognized that various modifications of both thedispenser and perforating mechanism of the invention may occur to thoseskilled in the art. Therefore the scope of the invention is to belimited solely by the scope of the appended claims.

We claim:
 1. In a dispenser for flexible sheet material including, achassis adapted to be attached to a wall, means operatively connected tosaid chassis for rotatably supporting a roll of flexible sheet material,means operatively connected to said chassis for guiding a web offlexible sheet material from said roll to a position to be grasped by auser so that the user may pull the web out of the dispenser, and amechanism operatively connected to said chassis for perforating said webat intervals therealong to divide the web into individual sheets, theimprovement wherein said perforating mechanism comprises, a rotatablymounted roller, a rotatably mounted knife positioned adjacent saidroller and having a radially outward portion defining a cutting edge forperforating the web as the web passes between the roller and the knife,said roller being operatively connected to said knife for synchronousrotation therewith and having a slot therein for receiving said radiallyoutward knife portion as the knife rotates past the roller, and meansassociated with said knife for orienting said cutting edge substantiallyin the direction in which said radially outward knife portion moves withrespect to the web during the entrance of said portion into said slot sothat when the portion enters the slot, the cutting edge will effectivelyperforate the web, and wherein said dispenser further comprises amechanism associated with said perforating mechanism for stopping therotation of said knife and said roller and thus arresting the movementof the web after a predetermined length of the web has been withdrawnfrom the dispenser, and a variable timing means associated with saidstop mechanism for controlling the period of time during which the stopmechanism is effective to stop the rotation of the knife and the roller.2. In a dispenser for flexible sheet material including, a chassisadapted to be attached to a wall, means operatively connected to saidchassis for rotatably supporting a roll of flexible sheet material,means operatively connected to said chassis for guiding a web offlexible sheet material from said roll to a position to be grasped by auser so that the user may pull the web out of the dispenser, and amechanism operatively connected to said chassis for perforating said webat intervals therealong to divide the web into individual sheets; theimprovement wherein said perforating mechanism comprises, a rotatablymounted roller, a rotatably mounted knife positoned adjacent said rollerand having a radially outward portion defining a cutting edge forperforating the web as the web passes between the roller and the knife,said roller being operatively connected to said knife for synchronousrotation therewith and having a slot therein for receiving said radiallyoutward knife portion as the knife rotates past the roller, and meansassociated with said knife for orienting said cutting edge substantiallyin the direction in which said radially outward knife portion moves withrespect to the web during the entrance of said portion into said slot sothat when the portion enters the slot, the cutting edge will effectivelyperforate the web; and wherein said dispenser further comprises amechanism associated with said perforating mechanism for stopping therotation of said knife and said roller and thus arresting the movementof the web after a predetermined length of the web has been withdrawnfrom the dispenser; and wherein said perforating mechanism furthercomprises a second rotatably mounted roller operatively connected tosaid first-mentioned roller for synchronous rotation therewith, saidknife being mounted on said second roller; and wherein said stopmechanism comprises a camming pin operatively connected to said secondroller for rotation therewith, a stop lever pivotally connected to saidchassis and having a cam follower and a stop lug integrally affixedthereto, said cam follower being positioned in the rotational path ofsaid camming pin, and said stop lug being movable into the rotationalpath of said camming pin upon the engagement of said pin with saidfollower for stopping the rotation of the pin and said second roller,and thereby stopping the rotation of said knife and said first roller,so that after said predetermined length of the web has been withdrawnfrom the dispenser a user may tear an individual sheet of the web fromthe portion thereof remaining within the dispenser along theperforations last-produced in the web by said cutting edge, and meansconnected to said stop lever for moving said stop lug out of therotational path of said camming pin so that after said individual sheethas been torn from said remaining web portion an additionalpredetermined length of the web may be withdrawn from the dispenser. 3.A dispenser as recited in claim 2, further comprising a variable timingmeans connected to said stop lever for controlling the length of time ofthe stop lug remaining in the rotational path of the camming pin.
 4. Adispenser as recited in claim 3, wherein said timing means comprises apair of resilient vacuum cups, one of said cups being attached to saidstop lever and the other of said cups being attached to said chassis,said cups being engageable in vacuum-gripping relationship when saidstop lug is positioned in the rotational path of said caming pin, andvalve means associated with one of said cups for regulating the flow ofair between the cups when the cups are in vacuum-gripping relationship.5. A dispenser as recited in claim 2, wherein the position of saidcamming pin is adjustable with respect to said second roller so thatsaid knife and said first roller may be stopped while said last-producedperforations are either inside or outside the dispenser.
 6. A dispenseras recited in claim 5, further comprising means operable when said knifeand said fist roller are stopped with said last-produced perforationsinside the dispenser for rotating the knife and the first rollerautomatically after said stop lug has moved out of the rotational pathof said camming pin so that the leading edge of the web will be movedoutside the dispenser to a position to be grasped by a user.
 7. Adispenser as recited in claim 4, wherein said one cup is made of arelatively hard resilient material and said other cup is made of arelatively soft resilient material to thereby minimize the compressionforce required to engage the cups in vacuum-gripping relationship.
 8. Ina dispenser for flexible sheet material including a chassis adapted tobe attached to a wall, means operatively connected to the chassis forrotatably supporting a roll of flexible sheet material, meansoperatively connected to the chassis for guiding a web of flexible sheetmaterial from said roll to a position to be grasped by a user so thatthe user may pull the web out of the dispenser, a mechanism operativelyconnected to the chassis for perforating said web at intervalstherealong to divide the web into individual sheets, said perforatingmechanism including a rotatably mounted roller, a rotatably mountedknife positioned adjacent said roller and having a radially outwardportion defining a cutting edge for perforating the web as the webpasses between the roller and the knife, said roller being operativelyconnected to said knife for synchronous rotation therewith and having aslot therein for receiving said radially outward knife portion as theknife rotates past the roller, a stop mechanism associated with saidperforating mechanism for stopping the rotation of said knife and saidroller and thus arresting the movement of the web after a predeterminedlength of the web has been withdrawn from the dispenser, and a variabletiming means associated with said stop mechanism for controlling theperiod of time during which stop mechanism is effective to stop therotation of the knife and the roller; the improvement wherein saidtiming means comprises a pair of resilient vacuum cups, one of said cupsbeing attached to said stop mechanism and the other of said cups beingattached to said chassis, said cups being engageable in vacuum-grippingrelationship when said stop mechanism stops the rotation of the knifeand the roller, said one cup being made of a relatively hard resilientmaterial and said other cup being made of relatively soft resilientmaterial to thereby minimize the compression force required to engagethe cups in said vacuum-gripping relationship, and valve meansassociated with said one cup for regulating the flow of air between thecups when the cups are in vacuum-gripping relationship.
 9. A dispenseras recited in claim 8, wherein said stop mechanism is adjustable withrespect to said perforating mechanism so that said knife and said rollermay be stopped while the perforations last-produced in the web bycutting edge are either inside or outside the dispenser. .Iadd.
 10. In adispenser for flexible sheet material including, a chassis adapted to beattached to a wall, means operatively connected to said chassis forrotatably supporting a roll of flexible sheet material, meansoperatively connected to said chassis for guiding a web of flexiblesheet material from said roll to a position to be grasped by a user sothat the user may pull the web out of the dispenser, a perforatingmechanism operatively connected to said chassis for perforating said webat intervals therealong to divide the web into individual sheets, saidperforating mechanism including a rotatably mounted knife-receivingroller, a rotatably mounted knife positioned adjacent saidknife-receiving roller and having a radially outward portion defining acutting edge for perforating the web as the web passes between theknife-receiving roller and the knife, said knife-receiving roller beingoperatively connected to said knife for synchronous rotation therewithand having a slot therein for receiving said radially outward knifeportion as the knife rotates past the roller, and a stop mechanismassociated with said perforating mechanism for stopping the rotation ofsaid knife and said roller and thus arresting the movement of the webafter a predetermined length of the web has been withdrawn from thedispenser; the improvement wherein said guiding means comprises arotatably mounted upper pinch roll positioned adjacent saidknife-receiving roller and spaced from said knife in the directionopposite to the normal direction of movement of the web through thedispenser, a rotatably mounted lower pinch roll positioned adjacent saidknife-receiving roller and spaced from said knife in the direction ofthe normal direction of movement of the web through the dispenser, saidlower pinch roll also being movable toward and away from saidknife-receiving roller, and biasing means for urging said lower pinchroll toward said knife-receiving roller, whereby the lower pinch rollmoves away from said knife-receiving roller against the urging of thebiasing means when a user initially pulls on the web so that the web ispulled tautly against the knife-receiving roller, and the upper andlower pinch rolls cooperate with the knife-receiving roller when theknife and knife-receiving roller are rotated to insure that the web isheld tautly about the knife-receiving roller. .Iaddend..Iadd.
 11. Adispenser as recited in claim 10 wherein said upper pinch roll also ismovable toward and away from said knife-receiving roller and wherein thedispenser further comprises an additional biasing means for urging saidupper pinch roll toward said knife-receiving roller. .Iaddend.